Red brass, capable of being hot-worked



Patented Dec. 4, 1 951 RED BRASS, CAPABLE UFBEING HOT-WORKED? 1 William E. McCullough, Detroit, Mich., assignor to Bohn Aluminum & Brass Corporation, Detroit, Mich., a corporation of Michigan No Drawing. Application September 10, 1948, Serial No. 48,771

2 Claims. (Cl. 75-1575) This invention relates to a red brass, capable of being hot-worked, i. e., rolled, forged, extruded, etc. It is particularly adapted for architectural purposes, but is suitable for other uses.

For ornamental metal work on buildings there has been a decided preference for a material having a reddish color, such as red bronze. A typical red bronze has the following composition: copper85%, tin-5%, lead-5%, and zinc-5%. But red bronze, due to its hot-shortness (tendency to crack at raised temperatures), cannot be hot-worked by rolling, forging, extruding, or similar processes. It has therefore been necessary in manufacturing parts such as hardware, Window frames, etc., that require properties not found in cast bronze, to use a yellow brass of good hot-working properties. The yellow color of this brass is objectionable, particularly when used in combination with red bronze.

The present invention solves this problem by providing a brass that has a satisfactory red bronze color in both the cast and hot-worked conditions. It can therefore be used for parts that must be cast, as well as for those that must be made by hot-working. It can also be used for wrought parts in combination with part cast from red bronze. In either case there will be a satisfactory matching of the preferred red color.

In addition to providing a satisfactory color, the red brass of the present invention provides good physical properties and machinability.

The new alloy consists of a copper base with an appreciable percentage of zinc and smaller amounts of other metals. A typical sample of the present invention has the following composition:

The above alloy, after being cast and extruded, was found to have the following mechanical properties:

1 Rod dia Yield Strength, Ultimate Tensile Per Cent 2" p. s. 1. Strength, p. s. i. Elongation I ilh-- 52, 300 89, 000 10 Commercial forgings were made from 1" extruded rod of the above alloy, and it was found to have satisfactory forging characteristics with metal temperatures of 1200-1250 F. The color 2 of the metal was the same reddish hue in the cast, extruded and forged conditions.

Experiments have indicated that the alloy of this invention may have the following range, with slight variations in the red color and in mechanical properties:

Per cent Copper 50 --55 Aluminum 0.5- 2 Manganese 0.5- 2 Silicon 0.5- 2 Lead 0 2 Other 0 2 Zinc Balance Preferred color and properties are obtained, however, by keeping within the following ranges:

Per cent Copper 52.75-53.75 Aluminum 1.5 2.0 Manganese 0.75- 1.25 Silicon 0.25- 0.75 Lead 1.0 2.0 Iron 0.25 max.

Zinc Balance It will be seen that the new composition may be classified as predominantly a beta brass, the percentages of metals other than copper being such as to avoid the presence of delta, gamma, or other harder phase constituents. It is suitable for the manufacture of door and window frames, stair railings, framing for store counters and showcases, and for hardware.

Other objects and advantages of the invention will be apparent to those skilled in the art.

I claim:

1. An alloy having the following composition:

Per cent Copper 50 to 55 Aluminum 0.5 to 2 Manganese 0.5 to 2 Silicon 0.5 to 2 Lead 0 to 2 Others 0 to 1 Zinc Balance 2. An alloy having the following composition:

Per cent Copper 52.75-53.75 Aluminum 1.5 2.0 Manganese 0.75- 1.25 Silicon -1 0.25- 0.75 Lead 1.0 2.0 Iron 0.25 max. Zinc Balance WILLIAM E. MCCULLOUGH.

(References on following page) 3 4 REFERENCES CITED OTHER REFERENCES The following references are of record in the Campbell's List of Alloys, published by the file of this patent: American Society for Testing Materials, 1930,

UNITED STATES PATENTS Page Number Name Date 5 Transactlons of the Amencan Foundrymens 1,551,443 Vaders Aug 25 1925 Association, vol. 44 (1936) pages 457 and 458. 1,907,219 Seig May 2; 1933 1,987,639 Roberts Jan. 15, 1935 

1. AN ALLOY HAVING THE FOLLOWING COMPOSITION: 